This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The purpose of this study is to evaluate serotonin function and aspects of GABA biology, in 30 women with the spectrum of PMS symptoms (20 with PMS: 10 with affective symptoms and 10 with predominantly physical symptoms), 10 with PMDD, and 10 controls. Citalopram will be used as a neuroendocrine probe to measure hormones regulated by serotonin, and the major neurosteroid progesterone metabolite allopregnalolone.